l1=['鲤鱼','草鱼','鲫鱼','鳙鱼','鲈鱼']
l1.append('黑鱼')
del l1[3]
l1[4]="鲶鱼"
print(l1.index('草鱼'),end="\n")
print(l1[1:3],end="\n")
di={'f1':['鲤鱼','杂食性'],'f2':['草鱼','食草性'],'f3':['鲫鱼','温水性'],'f4':['鳙鱼','温水性'],'f5':['黑鱼','肉食性']}
di['f6']=['鲈鱼','杂食性']
del di['f3']
di['f5']='鲶鱼'
ls=[]
for k,v in di.items():
   if v[1]=='温水性':
      ls.append(v[0])
print(ls)
    
  


    
